JPS5773538A - Selective callout system - Google Patents

Selective callout system

Info

Publication number
JPS5773538A
JPS5773538A JP55149139A JP14913980A JPS5773538A JP S5773538 A JPS5773538 A JP S5773538A JP 55149139 A JP55149139 A JP 55149139A JP 14913980 A JP14913980 A JP 14913980A JP S5773538 A JPS5773538 A JP S5773538A
Authority
JP
Japan
Prior art keywords
circuit
voltage
opposite polarity
signal
produced
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP55149139A
Other languages
Japanese (ja)
Inventor
Kiyoshi Iizuka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu General Ltd
Aerojet Rocketdyne Holdings Inc
Original Assignee
Fujitsu General Ltd
Gencorp Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu General Ltd, Gencorp Inc filed Critical Fujitsu General Ltd
Priority to JP55149139A priority Critical patent/JPS5773538A/en
Publication of JPS5773538A publication Critical patent/JPS5773538A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

PURPOSE:To avoid a transistor (TR) from being malfunctioned because of noise signals, by applying a voltage with opposite polarity to the power supply voltage to a base circuit of the TR in a decoder circuit. CONSTITUTION:An oscillating output signal of an astable multivibrator 22 is applied to a wave shape circuit 41 of a circuit 35 to produce a voltage of opposite polarity and to a switching circuit 31. An output signal shaped at a wave shape circuit 41 is applied to an inverse voltage rectifying diode 42, where the signal is rectified and smoothed at a smoothing capacitor 43. The voltage of opposite polarity thus produced is applied to the bases of TRs 17, 20... as switching elements via resistors 44, 45.... When a tone signal is inputted to an input terminal 2, the switching circuit 31 passes through an output of the astable multivibrator 22 and a callout tone is produced from a speaker 33.
JP55149139A 1980-10-24 1980-10-24 Selective callout system Pending JPS5773538A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55149139A JPS5773538A (en) 1980-10-24 1980-10-24 Selective callout system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55149139A JPS5773538A (en) 1980-10-24 1980-10-24 Selective callout system

Publications (1)

Publication Number Publication Date
JPS5773538A true JPS5773538A (en) 1982-05-08

Family

ID=15468601

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55149139A Pending JPS5773538A (en) 1980-10-24 1980-10-24 Selective callout system

Country Status (1)

Country Link
JP (1) JPS5773538A (en)

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